Co-leader of the Saxon (an inclusive term for Angles, Saxons, Jutes and Frisians) forces said by Geoffrey of Monmouth to have originally been imported into Britain as mercenaries by Vortigern. In return for land to raise their families, the Saxon troops were to protect the land from invasion by the northern Picts and Scots. Instead, the Saxons got greedy and broke out of their enclaves, wreaking death and destruction upon the defenseless Britons, until rescued from total ruin by Ambrosius Aurelianus, who, according to Gildas, stemmed the Saxon tide for a time.

Hengest (also spelled Hengist), probably a Jute, from Denmark, is said by the "Anglo-Saxon Chronicle (ASC)" to be the son of Wihtgils in a direct line from the god, Woden; the brother of Horsa and the father of Octha and Aesc. He is regarded by most, but not all, scholars as a genuine historical character. Some additional support for Hengest's historicity is to be found in a document called the "Finnesburh Fragment," part of a now-lost heroic poem, which mentions him:

. . .Then the stout warriors, Sigeferth and Eaha, went to one door and unsheathed their swords; Ordlaf and Guthlaf went to guard the other, and Hengest himself followed in their footsteps. . .

The fragment tells the story of a band of warriors who accompany the Danish prince, Hnaef, on a visit to his sister, Hildeburh, who is married to a man named Finn, the ruler of the Frisians. In a nighttime surprise attack, Finn's men kill Hnaef along with Hildeburh's sons (Hnaef's nephews) and overcome the other Danish warriors.

The epic poem, "Beowulf," in a digression from the main tale, contains more information about this event and from it we learn that, after Hnaef's death, Hengest assumed leadership of the Danes and became the servant of Finn, until he could take his revenge, the following spring.

The ASC has Hengest arriving in Britain in 449 and places his death in the year 488.